1) Have you priced other books?
2) Have you read any of the books in the series?
They are poorly written, but I think a good editor with the power to send the manuscipts back for second drafts could have repaired most of the damage.
An exmaple. As the author, when you're setting up the first major speech of the Antichrist, the one that's supposed to make the world fall in love with him, as a writer, you better deliver that speech. Even if you posit the speech's effectiveness is infernal rather than pedestrian, you are still obligated to present it and do your best to even for a moment sway your readers into the Antichrist's camp to demonstrate his power (a tall order, but that's what you shoot for). What you DON'T do, after building up this incredible "coming out" speech, is cop out by delivering a few lines then blurring over the rest by describing how impressed everyone was.
The writers completely ignore huge events which apparently don't interest them, like Barnes' setting up an underground network of Christian cells around the world, not to mention an entire second American civil war. These would have make incredible backdrops to the early part of the series. Instead, we get rushed through the first half of the Trib, then slow to an absolute crawl toward the end. (I know this was partly because the publishers woke up to the gold mine halfway through and begged them to drag the series out, but in the end, that's no excuse -- Tolkien rewrote the entire LotR saga in several stages over many years before publishing it.)
IMHO, of course. If you liked the books, pay no mind to my screed. ;)
I just started book seven (The Indwelling) last night.
I'm buying them in paperback (at Sam's or Wal-Mart) to save some bucks.
I agree with the assessment that the writing is pretty cheesy. But I find the story line fascinating even if I do have questions regarding the theology.